Earth Alliance is quoted (“And now for a word”) as having thirty colonies and outposts in over two dozen solar systems in 2259. Some are mining colonies or used for food/ fertilizer production while Beta 7 appears to be mainly used as a prison planet-cum-mental institution. Earth’s population is sometimes referred to as ten billion, sometimes as nine billion.

The colonies on Proxima 3, “the Orion colonies (three for Orion’s Belt?)”, Vega colony, Deneb 4, Arisia 3 and Beta 9 are all formally part of the Earth Alliance. The prefix ‘beta’ could refer to the second generation or phase of human colonization. Humans also have colonies on the planets Regula 4 and Theta 49, but these were both effectively colonized by separatists and were never formally EA protectorates or members despite some harassment by Earth Force!

The planet Ceti Gamma II is mentioned as being home to Pro Zeta Corporation. It may be outside EA jurisdiction.

The source for the following is http://www.chronology.org/b-five/ by the way.

The following colonies (and some planets) are mentioned in passing:  New Kobe: In By Any Means Necessary, Senator Hidoshi mentions that his grandfather worked in the spacedocks on New Kobe. (Note that Kobe is a major city in Japan; it's possible this was founded as a colony by a Japanese organization or political entity.)

Or it could be a city on Earth or a space station orbiting Earth.

 New California: There was a labor strike on New California at some point in time, according to By Any Means Necessary.

 New Jerusalem: Colonel Ari ben Zayn was involved in fighting here, according to Eyes. It is possible that this began as a Jewish colony or an Israeli colony.

 Cyrus III: Colonel Ari ben Zayn was involved in fighting here, according to Eyes.

 Janos VII: General Franklin led a military campaign here – in GROPOS, he is referred to as the "Scourge of Janos VII". The pterodactl-like Grylor in Knives is mentioned as being native to Janos VII as well.

Probably a low-tech level EA protectorate, which explains why Sheridan had some experience of the planet, presumably through his time on the Agamemnon or before.

 Amador and Pepinia: Two of Earth's newest colonies. Amador and Pepinia joined the Earth Alliance just before The Gathering, according to the headline in "Universe Today".

 Sinzar and Flinn Colony: These were sites of battles in 2247, during the latter part of the Earth-Minbari War, according to In The Beginning.

Is Flinn Colony the same colony as “Flinntown” or “Flintown” on Mars?

 Jericho 3: Another colony mentioned in ‘In The Beginning’.

 Disneyplanet: Garibaldi could be joking when he mentions Disney planet. Could it actually be a space station or hollowed out asteroid?

Some possible Earth Alliance/ human colonies/ space stations/ outposts (Expanded Universe): New London Station, Canton I Colony, Canton III Outpost, Kandhi III Colony, Berlin II Colony, Delphi IV Colony, and the Myoto VI Outpost, all of which sound like "national" colonies. The Cooke II Colony, Cooke III Colony, Dakota I Colony, Dakota II Outpost, Dakotat Colony, Leonis V Colony, and Leonis VII Outpost are also named.

Further worlds take their names from the stars where they are located: the Sirius III Mining Outpost, Sirius Transfer Station, Kapteyn's Station, Ceti Station, Ceti II Colony, Tau Ceti IV Colony, Wolf V Colony, Signet Station, Ross IV Outpost, Eridani III Colony, and the vanished Procyon II Colony.

Specific planets settled by humans mentioned in the EU are Betelgeuse 4 and 6, and Nippon.

In our Solar system, The Babylon Project adds the Venusian Orbital Station, Saturn Station, and the Skywalker Asteroid Base. It also names the colony on Earth's Moon as the “Armstrong Colony”.

Humans are mentioned as living on or visiting several other planets/ colonies but there is no indication that any of those are either exclusively human or EA protectorates, they are simply human-suitable worlds that some humans have visited and lived on from time to time. An obvious example of this is the fact that a character called “Alisa (or Lisa) Beldon” discovers she is a telepath. Instead of joining the Psi Corps she is allowed to live on Minbar. Presumably she is adopted by the Religious Caste, who presumably have jurisdiction over Minbari telepaths. Also, Lyta Alexander does live on the Vorlon home world for at least a week while they upgrade her telepathic abilities. A million years after the time Babylon 5 is set, humans migrate to Vorlon. This does not make Minbar or Vorlon part of the Earth Alliance.

Confirmed Earth Alliance planets (some are named after their star or stellar formation): Earth, Mars, Proxima III, Orion, Beta VII and IX (is this ‘Beta Durani’?), Vega, Deneb 4, Arisia 3, Ceti Gamma 2, Cyrus 3, Janos VII, Amador, Pepinia, Sirius III, Ceti II, Tau Ceti IV, Wolf V and Eridani III. This comes to nineteen. At least three are protectorates although I’d imagine only (apart from Earth) Mars, Orion, Proxima III and Vega Colony would be important enough to have their own Senator each. Orion colony or the Belt as it is sometimes referred seems to be a definite political entity on its own. A base was also established on Akdor after “Operation Sudden Death” (GROPOS).

Twelve more colonies are mentioned as being established by humans, some of which are probably in the same system if not the same planet. These are probably only nominally part of the Earth Alliance, politically its citizens probably have voting rights in the Presidential elections but they have no Senators.

There are also bases and colonies stationed on the Moon, Phobos, Deimos, Ganymede and Europa, as well as stations in orbit or near Venus (Lucifer), Mars (Lagrange 2), Io (Transfer Point) and Saturn, plus the aforementioned “Skywalker Base” in the Asteroid Belt, all in the home Solar System adding up to ten Earth Alliance installations.

The population of the different colonies and space stations is difficult to determine. A colony deliberately set up for ideological purposes, such as Mars, would start off with a small but self-sustaining population (200-600) but people live there because they want to live there, although some may work off-planet. Others, such as mining colonies and transfer points are populated almost entirely by transients and the people who work there. Babylon 5 is certainly one of the largest space stations built by man with a capacity of 250,000. This figure is certainly an upper limit for a space station and is a good estimate of the Lunar colony population as well. With the seeming importance of the Orion and Vega colonies, they may each have a population of 500,000. Mars is quoted as having a population of two million and is almost certainly Earth’s largest off-world colony.

The population of the off-world colonies and bases in the solar system may come to four million. 28 extra-solar colonies add up to a lower limit of 3.6 million but could be as many as 20 million. Assuming 20,000 personnel at thirty extra-solar outposts gives 600,000, although this figure could be much higher and there would be some civilian support staff and hangers-on. This gives population living or working outside Earth at 8.4 million. Adding the human population of Babylon 5 (125K) gives 8.5 million. The number of humans who are in transit between planets and bases or who live outside EA jurisdiction is hard to determine, but is probably at least 400,000. A lower limit for Earth Force personnel aboard starships at any time is two million, with an upper limit of eight million. As most Earth Force personnel would be on Earth or one of her bases four million is a reasonable estimate. The human population off-planet can be estimated, conservatively, at 12.9 million but a figure of around twenty million is likely, or sixteen million outside the home system.

The political situation. The Earth Alliance has an elected President and a legislative body of Senators from each member nation/ political bloc on Earth. They mainly dictate foreign and colonial policy with individual nations making their own laws. In the 23^rd century some of these ‘blocs’ are formed from several nations e.g. the African and Eastern so the number of Senators may be less than the current number of nation states in the 21^st century.

It is not known if any off-world colonies actually have Senators. Some colonies appear to be directly ruled by or on behalf of Earth while some have a degree of autonomy but the Earth Alliance receives 30% of planetary income.

Personnel stationed off-planet certainly have the right to vote in Presidential elections. Presumably citizens in all EA members can, but Earth Force personnel make up a significant portion of off-world voters. With regards to representation, if all or most colonies have a Senator each they could make up a bloc with the smaller nations on Earth. The larger political blocs, like China and the North American Alliance, have as much representation as each of the smaller blocs and colonies but their voters can make or break a Presidential election and probably field a greater number of candidates.

Off-world colonies seem to be divided into the following: those colonies that have a degree of autonomy and are represented by their own Senator, probably just Orion, Proxima III and Vega Colony; those which are directly ran by the EA, i.e. Mars, the outposts at Io and others, and protectorates such as Janos VII (which would be at least partially self-funding through Jumpgate fees paid by alien traders); those which are more or less left alone apart from the odd patrol, supply drop of educational supplements and tax collection; and those which are either completely independent or set up on behalf of an Earth national or religious group, in which case they may be represented by the parent nation on Earth.